Spring loaded bellows regulator

ABSTRACT

A pressure regulating valve includes a valve (22&#39;) biased closed against seat (21&#39;) by spring (7&#39;). An adjustment arrangement including nut (6&#39;) and shaft (3&#39;) is used to set the spring bias.

BACKGROUND OF THE INVENTION

This application relates to pressurized fluid systems and moreparticularly to an apparatus for regulating the pressure in the system.The invention will be described with particular reference to a pressureregulator containing a spring loaded bellows assembly but it will beappreciated that selected aspects of the invention may have applicationin related fluid environments and uses.

U.S. Pat. No. 5,303,734 discloses a predecessor regulator, thedisclosure of that patent being hereby incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take physical form in certain parts and arrangementsof parts, preferred embodiments of which will be described in detail inthis specification and illustrated in the accompanying drawings whichform a part hereof, and wherein:

FIG. 1 is a longitudinal cross-sectional view of the new pressureregulator formed in accordance with the subject invention; and

FIG. 2 is a longitudinal cross-sectional view of a modified regulatorused as a back pressure regulator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, there is shown a preferred embodiment of theinvention in which high pressure fluid enters inlet port A of body 19and then continues on to the poppet chamber B. The fluid's passage fromchamber B to chamber C through the orifice 20 is controlled by theopening between the movable poppet 22 and the orifice seat 21. After thefluid enters chamber C, it exits the body 19 via the outlet port D. Thefluid pressure in chamber C acts against the movable bellows face plate16, which is connected to the poppet stem 18, which extends through theorifice 20, The poppet stem is, in turn, connected to the poppet 22. Thebellows face plate 16 is welded to a flexible bellows 15, which iswelded to a bellows support collar 14. The bellows support collar iswelded to an upper housing 17, which is welded to a main body 19.

One prefeaed form of bellows 15 includes a series of annular members ordiaphragms that are alternately secured at radially inner and outerregions to define an accordion-like arrangement. Such a bellowsarrangement has a relatively small stack height in a fully collapsedcondition.

The pressure acting on the bellows face plate 16 is counteracted by aregulator spring 7 which pushes on the opposite side of the face plate.When the pressure in chamber C overcomes the force exerted by theregulator spring, the face plate yields to the greater force and movesupward, moving the poppet stem and poppet until the poppet seals againstthe poppet seat. Once the poppet engages the seat, further flow isstopped and a corresponding increase in pressure occurs. As flow exitschamber C through the outlet port D, the pressure in chamber c isreduced and the regulator spring force then exceeds the fluid force onthe face plate. This causes the face plate, the poppet stem, and thepoppet to move downward thereby opening the orifice passage and allowingflow to resume.

The pressure setting can be varied by adjusting the amount of regulatorspring force. This is accomplished by turning adjusting knob 1 which isattached by set screw 2 to adjusting shaft 3. Threaded onto theadjusting shaft 3 is a spring compression nut 6 which is prevented fromturning because its hex points slide in grooves machined into springhousing 5. Hence as the adjusting shaft rotates, the spring compressionnut axially advances or retracts applying increased or decreased springforce on the back side of the bellows face plate 16.

In addition to the above main concept, the regulator has a mechanism forpreventing oscillations or vibrations. This is accomplished by an O-ring10 housed in an O-ring catch 9 that fits tight over a damper shaft 12.This arrangement exerts a slight resistance to movement of the bellowsface plate 16 as it responds to rapid pressure changes. The damper shaft12 is provided with a taper so that just as the poppet is about toclose, the O-ring's tight fit diminishes so as not to resist the sealingforce necessary to stop all flow between the poppet 22 and the orificeseat 21.

Another feature of this regulator is return spring 11. This springassures that when the adjusting knob is turned to fully retract thespring compression nut, and therefore, all regulator spring force, thebellows face plate will move upward and the poppet will be urged to movetightly against the orifice seat.

Welded to the bottom of the main body 19 is a body base 23 which has anaccess port to service the poppet 22. This port is sealed by a gasket 24being pressed against a seat by a set screw 25.

In a second preferred embodiment shown in FIG. 2, the poppet 22' islocated in chamber C for sealing on the upper or opposite face oforifice 20'. In this arrangement, the assembly can be used as a backpressure regulator in which the port D becomes the inlet and the port Ais the outlet. The poppet stem 18' is of reduced length and the poppet22' is inverted relative to the FIG. 1 configuration to seal on theupper seat. In this manner, the pressure in the inlet D acts on thebellows and regulator spring to provide a predetermined pressure atwhich the poppet is lifted from the seat. This controls the fluid flow(and pressure) to the outlet A as desired with a back pressureregulator. In substantially all other respects, this embodiment isstructurally and functionally identical to the FIG. 1 embodiment.

The invention has been described with reference to the preferredembodiment. Obviously, modifications and alterations will occur toothers upon a reading and understanding of this specification. It isintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims or the equivalentsthereof.

Having thus described the invention, it is claimed:
 1. A pressureregulator comprising:a housing having an inlet and outlet communicatingwith a chamber and a seat interposed between the inlet and the outlet; apressure responsive member disposed in the chamber between the inlet andthe outlet for controlling fluid flow from the inlet to the outlet andincluding a spring for urging the pressure responsive member open untilthe fluid pressure in the chamber reaches a selectable pressure setting,said spring isolated from the chamber, said pressure responsive memberfurther including a flexible stacked diaphragm bellows, a movablebellows plate and a seal member operatively associated with the bellowsplate for selectively engaging the seat in response to the pressure inthe chamber, said bellows secured to the housing at a first end andsecured to the bellows plate at a second end; an adjustment member forselecting said pressure setting of the pressure responsive member, saidadjustment member connected to the bellows plate through a damper havinga tapered region that receives an elastomeric member to eliminatevibrations; and a return spring for urging the pressure responsivemember toward the seat when the adjustment member is fully retracted,said return spring isolated from the chamber.
 2. The pressure regulatorof claim 1 wherein the adjustment member includes a shaft extendingthrough the housing and threadably receiving a movable nut memberthereon, the movable nut member having an external surface closely andnon-rotatably received in the housing, and wherein the spring has afirst end that engages the nut member and a second end that engages thebellows plate.
 3. The pressure regulator of claim 2 wherein theadjustment member further includes a set screw and an adjusting knob,wherein the set screw connects the adjusting knob to the shaft.
 4. Thepressure regulator of claim 1 wherein the pressure responsive memberincludes a poppet extending therefrom for selective engagement with theseat.
 5. The pressure regulator of claim 1 wherein the bellows comprisesat least two flexible annular diaphragms alternately stacked and securedto one another at radially inner and outer regions.
 6. The pressureregulator of claim 1 wherein the spring and the return spring areexposed to atmosphere.
 7. The pressure regulator of claim 1 furthercomprising a bellows support collar, said collar interposed between thebellows and the housing such that said collar is secured on a first endto the first end of the bellows and secured on a second, opposite end tothe housing.